Automatic telephone system and apparatus.



APPLCATIDN FILED MAR 28 190? HENEWED MN 2 1,267,097.

T. G. MARTIN. AuToMATlc TELEPHONE SYSTEM AND APPARATUS. APPLICATION FILED IME. 26. i901.

RENEWED MN. 28. |918.

Patented May 2l, 1918.

2 SHEETS-SHEET 2.

f/ 3 A .6 T. .n 77 .N aww... m uw u raf /5 u u u wrlu/ w, W W f W mn u U/ c ww w a UNITED STATES PATENT oEEIoE.

TALBOT G. MARTIN, 0F CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS. T0 AUTOMATIC ELECTRIC CO., A CORPORATION 0F ILLINOIS.

AUTOMATIC TELEPHO E SYSTEM AND APPARATUS.

Application mcd March 26. 1907, Serial No. 364,699. Renewed January 28, 191B.

To all whom z't mag/concern:

Be it known that I, TALBOT G. MARTIN, a citizen of the United States of America, and resident of Chicago, Cook county, Illinois, have invented a certain new and useful Improvement in Automatic Telephone Systems and Apparatus, of which the fol lowing is a specification.

My invention relates to telephone systems in general. but more particularly to automatic systems in which step-bystcpactuated and electrically-propelled switches are cmployed for extending connections, and more especially to systems in which the electri cal current for talking,r purposes is supplied from means located at the exchange or central station.

As herein disclosed, I provide an auto'- matic switch provided with means for automatically skipping `busy lines and stopping on the first idle line, so as to automatically select thc first idle one of a plurality of lines. and provided also with means for controlling the tion' of talking;r current to the calling and called telephone lines. In this way the said automatic switch combines the functions of a selector with those of a connector, and in addition has control over the supply of talking current to the calling and called telephone lines, or at least to the called telephone line. IVilh this arrange ment a subscriber may have several telephone lines running to his substation, and with an automatic switch of this character the callin subscriber will automatically select the rst idle one of said lirios.y somewhat in the manner that a selector operates to select the first idle one of a number of trunk lines. If the called subscriber has a. number of telephone lines` it does not. of course. make any difference to the calling suhseriber'whieh of said lines is employed by him in extending connection to the substation of the called subscriber. With my improved system and apparatus the calling subscriber can call the number of the called substation, and the switch for completing the final connection will automatically Search through the lines of the called subscriber and sto on the first idle line, which would be the rst of said lines if none are busy. In addition, the said automatic Iswitch for thus making the final connection will Specification of Letters Patent.4 Patented Blny 2] 1.91 S.

Serial No. 214,253.

then, in response to the act of the called subscriber in taking down his receiver, adt 'will answer the purpose of the calling subscriber.

To the foregoing and other useful ends, my invention consists in matters hereinafter set forth and claimed.

In the accompanying drawings, Figure 1 shows diagrammatically a calling substation A and a called substation A connected through the medium of a common battery central office comprising rotary connector switches. In the said central ottico the calling substation #500 has allotted to its line a. first-selector C of the general type disclosed in United States Patent No. 815,321, granted March 13, 1906, to Keith, Erickson & Erickson. It Will loe seen that the central battery B has its positive terminal preferably grounded at G. The operating relays of the central switches are normally connected to the non-grounded terminal of. said battery, so that the subscriber by grounding his line conductor may operate the said switches, as is usually the custom in systems of this type. In addition to the first-selector @there is shown at D a com mon battery rotaryr connector switch, and at E is shown another first-selector (similar to the selector C) allotted to the called line; said selectors and connectors respond to the numeral operations of the calling subscriber and for that reason are some times spoken of as numerical switches. In this system both the callin(1r and called substations are provided with Lbattery current for talking purposes only when the called subscriber answers.

n l Fig. 2 1s a diagrammatic perspective View of the rotary connector which is an improvement upon the general ty e of connector disclosed 1n United States atent No. 815,176, granted March 13, 1906, to Keith, Erickson & Erickson. In the connector DI provide means whereby the connector shaft may be automatically rotated (like the shaft of a irst-selcctor) when the private wiper engages grounded contact points. My improved connector combines in a common bah tery switch the general features of the switch disclosed in said connector patent vwith the automatic selective features of the switch disclosed in said selector patent.

The substations may be of any suitable or approved type. The substation A, for example, comprises a receiver 2, switchY hook 3, induction-coil which consists ot the primary Winding 5 and secondary wind-- ing 6, transmitter 7, condenser 8, rin er 9, impulse wheel 10 which has the usua vertical impulse teeth ll that are adapted to operate the vertical impulse spring 12. The impulse Wheel carries the rotary impulse tooth 13 which operates the rotary impulse spring 14. The switch-hook has radiating from its body a number of cam-arms 15, iti and 17 and is pivotally secured to the keyboard (not shown) by the screw 18 about which it moves when the receiver is reH moved. The movement is produced by a spring (not shown), and the switch'hoolt pushed up for the purpose ot' changing certain circuit connections to be disclosed. 'llie cam-arm 15 controls the so-ealled loclv ing cam 19. After the dial is rotated the loekin'g cam 19 occupies the position shown at substation A, permitting the ground springs 2O and 21 to engage, and thus placing,r the ground post QQ in connection with the substation ground (l. whereby when the subscriber releases the dial after rotating it, as described, the vertical impulse teeth vll will cause the vertical impulse spring 1Q lo come in contact with the ground post QQ: and immediately after, the rotary impulse tooth lB causes the rotary impulse spring lil to come, in contact with the same `,ground post 2Q, thus sendungr ground impulses to the central olliee for operating the switches thereat But while the `with-hook is down the locking cam it) occupies the position shown at substation A. thus locking thc dog 27, whereby the shall' to which the dog is attached is prerenled from heilig turned by the dial` which latler is not shown but which may be oi' any type usually employed at a substation oi' the chariurter in question. Also. the cam-arm 17 maintains a contact between the springs S and 2l. thereby bridging the condenser o in .series with the ringer 9 across the line. and maintaining the springk and *1h diwne'agged, whereby the priniar rirruit including" the winding T in series. with the transn'iilier 7 is interrupted. The signaling? derive wherel'rv a subscriber nini' `ifnal another after :i connection has been eslahlished comprises a` pusli-hutton 2h and a spring 29. which lat-- ter normally engages the contaet point 30,

but when thepiisli-biitton 28 is pressed the spring 29 leaves the contact point 30 and engages the contact point 31 which is connected with the. substation ground G. Means whereby the subscriber may release th'e central Station apparatus brought into service comprises three springs 3Q, 33 and fil, known as the release springs, and so controlled by thc eanrarm 1G that when (he switehhook descends the three release springs` are brought into contact for a mo nient. thereliy grounding both the .sub- `srriher`s line conductors simultaneously.

',lhe first-selector switch shown at. C, being oF the type described in the said selector patent, is well known and needs only eneral description. vThe switch shaft not shown) carries the vertical and rotary wipers 39 and 40, respectively, and the; private wiper 4l. The side switch is also well known. and comprises the side switch wipers 12. ifi, 'll and 45, which may be designated as the vertical` rotary' and prirale side switch wipers and the rotary magnet sidc switrh wiper, respectively. The fide switch is under the control oll the privite magnet lliA and through the inediiun of the iertit'al line relai' -li' the .siilisrriluu ciuili'riis: the tei*- tiral magnet-1f?, while the aide switch is in thc first position. which latter magnet. operates to raise the shaft and shaft wipers 30. 40 and 4l vertically. The private mag net., however, is controlled through the me diuin ofthe rotary line relay 479. Thilo the side switch is in second position, the rotary magnet (which carries the shaft and Shaft Wipers in a rotary or circular direction) is energized, in a local circuit, and the vertical and rotary line relays 47 and 49, acting eonjointly. provide means whereby the subscriber controls the release magnet 5l while the said side switch is in first or seei'iud position. However, after the side switch passes to third position. then., since the first-selector is oi the trunlrlelcase type, the said switch is controlled through the medium of the next switch D, with which a connection is established, over a circuit eoinprisino' the private wiper 4l and the baelereleasc relay 52. The bridge-cutoff relay 53 is provided to open the connection between the line relays 47 and 419 and bctween the said relays and battery B, This is desirable` because it' thc relays are not disconnected from cach other and battery the ringing current for signaling` the subscriber may operate to throw thc selecton switch C oft' normal. lt is also desirable to remove the bridge formed through the said relays troni across the line to give the voiceeurrents as clear a path as possible. 'The irsbselector switrh-shai't is also provided with a normal post arm 54 which. when the shaf t is in normal position, elosesthe spring 55 in contact with the contact point 56; butI vate banks 68 and 69.

when the shaft is raised one or more ste s the spring 55 closes in contact with t e contact point 57, by which switching means the line allotted to the switch is made busy while the switch-shaft is off-normal. Also,

-the energizing circuit for the relay 53 comprises the spring 55 and contact point 56.

The connector switch D (Fig. 2), as has been stated, is an improvement upon the one disclosed in the said connector patent. The mechanical details are very much the same, although the circuits are materially different. The usual switch shaft 64 of said connector is provided with the line wipers 65 and (i6 and with the private wiper 67, which have allotted to their use the line and pri- Said Shaft is also provided with the cam 70, longitudinal teeth 71, circular teeth 72, normal post arm 73 and coil spring 74. Said switch is also providedwith vertical and rotary line relays 75 and 76, and the vertical and rotary magnets 77 and 78, the release magnet 7 t), private magnet 80, ringer relay 81, and the vertical and rotary `back-bridge relays 82 and 83, respectively. The side switch F performs, as usual, switching operations through the medium of the side switch Wipers 84, 85, 86 and 87. lt`u1'thermore, the connector 1s provided with a differential relay S8 which comprises the windings 89 and 90. in addition provided with the private relay 91 which is controlled by the rotary line relay T6, vwhich relay 91 in turn controls the private magnet 80, as will be hereinafter explained. The said private relay is the'link that connects the old features of the connector with the selective feature to which reference has been Iliade. The object in providing the connector with this automatic selective feature is as follows: A business olice, for example, may be provided with three substations, all of which are given the same number, and it becomes desirable to soarrange the system that if one telephone is in use the connector switch will automatically carry thc calling subscril'ier into connection with the second telephone. and if the second telephone is also in use the con ncction is ca rricd to the third telephone, and so on. ln that case there would, of course, bc one line for each telephone terminating fit a given set of connector I'ianks. The call ing subscriber would have no control over thc apparatus' as to which one of the set of telephones be makes connection with. This, ot' course docs not concern him. since, for the purpose ola his transaction. any telcphonc at the `said oflice will do. The arrangement of the connector baldo' themselves will be as follows: lf an office to which the number lll is allotted Wishes threeY telephones. the subscriber will be given three lines terminating one in the first :et of contacts ol' the first level of the connector banks,

This connector is another in the second set of contacts of the first level, and the third in the third set of contacts of the first level. N 0W, if the number 111 is called, the connector is raised to the first level and thenrotated into engage ment with the first set of contacts of the first level, but if the said first set of contacts are busy the connector is automatically rotated onto the second set of contacts, and onto the third set if the second Het of contacts are also busy. It bccomesdesirable, of course, to provide means for signaling thecalling subscriber in the event that all three of the lines are busy. For this purpose the fourth set of bank contacts of the first level are con nected with a busy-signaling circuit, at which contacts the connector must sto all events. The private contact 176 o the fourth set and corresponding contacts in the banks of all other connectors adapted to conneet with this group of lines are disconnected from each other or may be made of insulating material to prevent them from receiving a guarding potential from any other switch. In this particular illustration therefore, if the first three sets of contacts are busy the connector wipers will be rotated to the fourth set where they must stop rotatin and permit the side switch to passto thir position. A. busysignaling current is then sent out to the calling subscriber-Tsl line over a, circuit including the fourth set of contacts of this level, notifyin him of the state of affairs. It will be evident that any office may be equipped with telephones which may be numbered 155 and to which may be allotted one, two, three, or any number of lines, depending' upon the number oi contacts in the bank, reservin the last contact for the busv contact. lf 1t becomes desirable, one whole level may be designated by one number; but ordinarily it is expected that each level will be divided up into sets, one number foreach set the number depending upon the position of the first contact of the set in the bank.

The operation of the system may be more clearly disclosed if each step during the process of a call is followed in detail, as in the following: lt will bc assumed that the subscriber at substation A wishes to call the office or substation which is numbered 125 and which is provided with substation' telephoiu` sets A'. A2 and A. ofi which only is shown. When the receiver is removed from the switch-hook 3 the cant-arm 17 permits the springs Q3 and 24 to disengage, and the springs 25 andQfi to engage, thereby removing the ringer 9 from across thc linc and bridging instead the primary circuit.

The first digit being l the subscriber operates his dial accordingly, and as soon as the dial is drawn down the ground springs 2f) and 21 come into contact: establishing a ground connection from the substation ground G to the ground post As the dial returns, therefore, the impulse wheel 10, by aieans of the first one of the vertical impolsi,y teeth 11,' thrusts the vert-ical impulse spring 12 against the ground post 22 once, and then the rotary impulse tooth 13, in a similar manner Dresses the rotary impulse sprin 1t onto the ground post 22 once. The bnc conductors 92 and 93 are, therefore, cach grounded once, and as a result the vertical llne relay 4T of the selector (l is lirst energized by a tion of current from the sub st ation ground G through the ground springsy .20 and 2l to the vertical impulse spring t2, thence to the vertical line conductor 92, side switch wiper 42, contact point 04. vertical line relay 47, bridge-cut-ott relaiv springs` 95 and 90 tothe batteryv lead 97, and through battery B to ground Gr. The verti cal line relay 47 then, upon energizing once, presses the line relay springs 98 and 90 into contact, thus energizing the vertical magnet 4S once by a dow of current from ground G2 through the springs 98 and 99, private springs 100 and 101 to the vertical magnet 4S. thence to the battery lead 97 and through battery B to ground G. The vertical niagm-t 18, therefore. operates to raise the shaft wipers 39, 40 and 41 to the tirst level, in a well known manner. This operation having been accomplished, then when the rotary line conductor 03 is grounded the rotary line relay 40 is energized and this in turn operates the private magnet 46, which latter then trips the. side switch to second position. establishing an energizing circuit through the rotary magnet 50 for rotating the. Wipers onto some trunk line. The energizing circuit through the said rotary line rela 49 tends from the substation ground l' to the ground post 2:2. thence to the rotary impulso spring 14, rotary line conductor 93, side switch wiper 43. Contact point 102, rotary line relay 49, bridge-cut-o relay springs 103,

95 and 9G to the battery lead 9T, thencethrough battery B and to ground (i. The said rotary line relay. upon pressing the spine; 104 onto the spring 98, closes an enen gizing circuit through the private magnet 4G, as already Stated, from ground G2 through the springsQS and 104 to the said private magnet 46, thence to the battery lead 97, and th rough battery B to ground G. The private magnate, upon operating once, permits the side switch toV pass to second position, at which time the side switch wiper 45 enga ges; the grounded contact point. 105. whereby the energizing circuit for the rotary magnet 50 is closed from ground (i3 to the contact point 105, sidesvitch wiper 45, interrupter springs 100. rotary magnet 50 to the battery lead 07, thence through battery B to ground G. The rotary magnet is then energized and the wipers 39, 40 and 41 are carried into engagement with the first trunk. H the said trunk is not busy. as is Well known, the armature of the. rotary magnet 50, by inechanicall operating the armature of the private net 4G, releases the side switch to third posi tion; but if the said trunk is busy the private magnet energizes at the saine time that the private armature is depressed and at the instant that the private. wiper 41 engages the grounded contact, so that the side switch is held in second position, and an cnergizing circuit maintained through the rotary magnet fr0 until the priiiate wiper 41 is carried onto an idle trunk, and the energizing circuit for the private magnet destroyed. .\l the same instant that the side switch passes to third position, the wi per 45 learcs the contact point 105, thus breaking the encrgizing circuit for the rotaryv magnet 50 and bringing the selector to a standstill. The passage of the side switch to third position, of course, carries the side switch wipers 42 and 43 onto the Contact points 1.07 and 10S, .whereby the line conductors 92 and 93 are placed in connection with the line wipers 39 and 40 which, having already entered into connection with the trunk conductors 109 and 110 that lead to the connector D, place the said conductors 512 and 92S also in connection with the said connector D. The paesage of theside switch to third position, fui-then more, establishes a guarding potential :n the private wiper 41, when the side switch Wiper 44 engages the gromidcd contact point M1, to n'otect the seized line. This potential arrives at the said private wiper 41 from ground G* to thtl contact point 111, through the baclereleuse relay 52 to the private Wiper 41, The line conductors` 02 and 93 having been thus extended to thc connector D, the succeeding impulses Jfrom the `substation A are directed to said connector D.

The second digit heine' 2, the subscriber operates his dini accordingly. grounding the vertical line conductor ft2 twice. and the rotary line conductor 03 once. `Each time Vthat the 'vertical line conductor is grounded the verticahline relay of the connector D is energized lu' a [ion of current from the substation ground fi to the vertical line conductor 92, thence through the selector side switch 4Q to the contact point. 10i. rertical line Wiper 30, rertieal trunk conductor 109 to the vertieai line relay 75, thence through said relay and through the winding S9 of the relay 8S to the battery lead 0T, and from battery B to ground (i. Since the winding 89 is included in the energizing circuit of the vertical line relay, the relay 8S becomes energized, but` its oieration at this particular time is Without e ect. Each time that the vertical line relay 75 attracts its armature it torres the line relaiv springs 113 and 113 into contact. cach time sending` an impulse through the vertical magnet 77 from ground C through the said springs 112 and 113, conductor 114. private springs 115 and 116, conductor 117 to the vertical magnet 77, contact point ,11.8, side switch wiper 84, thence to battery lead 97, and through battery B to ground G. The vertical magnet, as disclosed in the aforesaid connector patent, when energized operates to raise the switch shaft and wipers. The vertical magnet 77 being energized twice, the wipers 65, 66 and 67 are raised to the second level. The ground impulse to the rotary line conductor 93, after the switch shaft 64 has been raised, energizes the rotary' line relay 76 of the connector, which in turn operates to energize the private relay 91. The circuit over which the said rotary line relay 76 is energized extends from the substation ground G to the rotary line conductor 93, thence to the side switch wiper 43 of the selector C, contact point 108. rotary line Wiper'40, rotary trunk conductor 110 tothe said rotary line relay 76, thence through the winding 90 of the differential relay 88, through the ringer relay springs 121 and 122 to battery lead 97, and through battery B to ground G. The rotary line relay 76, upon attracting its armature for a moment, forces the spring 35 onto the spring 112 for a moment, whereby a flow of current is sent through the private relay 91 from ground G5 through the springs 112 and 35, conductor 119 to the private relay 91, thence through conductor 120, ringer relay springs 121 and 122 to the battery lead 97, and through battery B to ground G. The private relay 91, upon energizing, operates to disengage the springs 123 and 124 to prevent an cnerg'ization of the rotary magnet 78 at the wrong time. Said relay 91 also operates at the same time to place the springs 125 and 126 in contact` whereby a momentary energizing circuit is closed through the private magnet 80, said circuit extending from ground G" through the springs 125 and 126, conductor 127, private magnet 80,

conductor 120, ringer relayl springs 121 and 122 to the battery lead 97. thence through battery B and to ground (i. The private muguet 80, upon attracting its armature and then denergizing, operates` as disclosed in said patent, to release the side switch F from first to second position. The effect of the shifting of the side switch is to substitute the rotary magnet 78 for the vertical magnet 77 to the control of the vertical linerelay 75 when the side switch wiper 84 leaves the contact point 118 and engages the contact point 128.

The third digit being 5, therefore-when the vertical line conductor 92 is grounded five times by the subscriber upon operating the dial corresponding-to the said digit-,the vertical line relay -75 energizes tive times over circuits that are now known, which relay in turn causes the energization of the to the rotary magnet 78, ,contact point 128,

side switch Wiper 84` thence to the battery lead 97, and through battery B to ground G. The rotary magnet 78 being energized five times the shaft 64 is rotated live steps, as explained in said patent, whereby the Wipers 65, 66 and 67 are carried into engagement with the fifth se't of contacts of the second level, from which contacts lead the normal conductors 129, 130 and 131 that extend to the selector E of the called line, the first two of which conductors continue through to the called 4substation A. After the connector has thus been operated the ground impulse to the rotary line conductor 93 encrgizes the rotary line relay 76 of the connector over circuits that are already well known, which relay in turn operates the private relay 91 as before. Now, when thelast rotary impulse operates the rotary line re lay 76, one of two results occurs, "namely the release of the side switch from second to third position, or the connector shaft is automatically rotated onto the next set of contacts, providing the first set of contacts is busy, and into connection with a second telephone A2. Also, if the second set of contacts leading to the otliee desired is busy, the connector shaft wipers are rotated to the next line which leads to a third telephone A3. Furthermore, if all of the trunk lines to which the number 125 is allottled are engaged, the shaft wipers are rotated onto a set of contacts to which the busysignaling machine 1 is connected, and the calling subscribcr receives the busy-signal. This automatic rotation is brought about as follows: When the private relay 91 encrgizes, the private magnet 8O is energized` as previously explained. and is maintained energizcd if the tit'th priva te contact is ground ed-that is, it the first line is in use. The holding circuit for the private magnet extends from the grounded contact to the private wiper 67, side switch wiper 85, contact point 132, conductor 133, private magnet springs 134 and 135, private magnet 80, conductor 120. through the ringer relay springs 121 and 122 to the battery lead 97, thence through battery B and to ground G. The private magnet 80 is thus energized by a locking circuit and retains the side switch wipers in second position as long as the wiper 67 engages a busy or grounded eon tact. Furthermore, when the private magnet is energized the spring 116 is shifted out ot' contact with the spring 115 and into contact with the spring 136, whereby a new energizing circuit is completed through the rotary magnet 78. This circuit extends from ground G7 through the interruptor springs 16T, ermduclor 138, private relay springs 121 and 1225, conductor 139, private magnet sfu-ings 136mm 116, conductor 11T, rotary magnet 7S, Contact point 128, side switch 9wiper 84 to the battery lead 97, thence through battery B and to ground G. The connector now operates to rotate automatically as long as the shaft wiper 67 'engages a grounded Contact point. Then the shaft wiper 67 leaves the last busy contact the circuit through the private magnet is broken, whereby the said magnet denergizes and the side switch passes to third position. If the first set of contacts is not in use there is no ground potential at the private Wiper 67 to lock and hold the private magnet when the last rotary impulse comes, and therefore the side switch passes to third position. At any rate, when the side switch passes to third position, whether the shaft Wipers are on the first line or after they have been rotated to another line7 the side Switch wiper 85 engages the Contact point 140, whereby a guarding potential is csf tablished at the connector private bank for protecting the seized line. Assuming that the connector has arrived on the line leading to station A', this rguardingpotential closes an energizing circuit through the bridge-cut-oi' relay 141 of the first-selector E. Also, the instant that the side switch wiper 85 engages the grounded mutant point 140, an energizing circuit is established through the ringer relay S1 extending from ground G to the contact point 140, side switch wiper S5, ringer relay` 81, conductor 142, springs 143 and 114, Contact point 145, side switch wiper 64 to the battery lead 97, thence through battery B and to ground G. The ringer relay, upon energizing, operates to shift the springs 116, 147 and 121 out of Contact with the springs 149, 150 and 122 and into contact with the springs 152, 153 and 131, resiiiectively. The engagement of the springs-146 and 152, and 11T and 1:33, places in contact the extended railing' line conductors and the called line conductors. The disengagement ot the spring 121 from the spring 122 to engage- Jnonl with the spring 154 changes the polarity ot' the conductor 120 from the battery load 9T to the ground mndurtor 156. Now

when the signal button 28 is pressed thf ringer relay 81 becomes denergized, whereN by theringer generator ll becrfrnu-s isridged across the line of the called subscriber. When the button 2S is pressed the spring 29 engages the grounded contact point 51. thereby grounding'the vertical line cond uctor from ground Gr through the springs 2U and 21, contact point 31, spring 2D, springs 26 and 25, vertical line conductor 92, thence to the connector vertical line relay 75, winding 89 of the dii'erential relay S8 to the battery lead 9T, thence through battery B and to ground (i. Since the winding 89 is included in this circuit, the reiay becomes energized and operates to disengage the springs 1&3 and 1414, whereby the energizing circuit through the ringer relay is broken. The ringer relay thon denergizrs and the ringer relay springs come back to normal position, whereby the ringer generator is bridged across the called iine conductors and a. naling current is sent from the generator H through the. springs 149 and 146, side switch wiper 87, Contact point 158, shaft Wiper 66, rotary normal conductor 130, line conductor 159, springs 160 and 161, ringer 162i con 'denser 163, vertieal iine conductor 113-1-, rertical normal conductor 129, shaft wiper 65,

signal, removes the receiver 166 from the switch-hook 16T, which latter upon rising allows the springs 168 and 169 to engage. thereby closing an energizing circuit through the back-bridge relays and S3 ein tending from ground Gg, contact point 110, side switch wiper S5, rotary haelt-bridge relay 83, through the ringer relay springs and 116, side switch wiper Si', contart point 15S, switch shaft wiper 66, normal confini tor 130, rotary ,line conductor 159, primary Winding 170, transmitterl'i'l, springs 168 and 169, vertical line conductor 164, normal eondoctor 129, switch shaft wiper 65, Contact point 165, side switch wiper 86, ringer re lay springs 147 and 153, through the windingof the coil S2 to the battery lead 9T,

thence through battery B and to ground G.

lThis circuit provides the called substation with battery current for talking purposes. l `urtherinore, when the relay 83 energises and closes the springs 172 and 173 in con tact, a circuit is closedmwhich provides the calling substation A with battery current for talking purposes. This circuit extends from ground GS. Contact point H0, side switch wiper through the springs 172 and 1723, ringer relay springs 15% and 121, conductor 120. winding 96 of the ditierential relay 88, rotary line relay 76, rotary trunk conductor 110, shaft: wiper 10, side switch wiper 43. rotary line conductor 93, primary winding 5, transmitter T, springs 26 and 2S, Vertical line conductor 92, side switch wiper 42, shaft wiper 39, trunk conductor 109, vertical lino relay T5, winding 89 of the differential relay 88 to the battery lead 97 thence through battery B and to ground The two substations heilig 'provided with battery current for talking purposes, the subscribers may hold communication over the circuitshown by the heavy lines in' Fig. 1. Assuming that all the lines 125 are usy, then instead of making connection the shaft wipers 65, 66 and 67 are rotated tothebusy contact points 174, 175 and 176, respectively, Fig. 1, and the calling subscriber receives the busy-signal from the busy machine I to the contact point 174, wiper 65,contact point 165` side switch wiper 86, ringer relay springs 147 and 153, through the condenser 177, thence over the vertical conductors, as pre viously traced, through the substation to the rotary line conductors and through the condenser 178, ringer relay springs 152 and 146, side switch wiper 87, contact point 158, shaft wiper 66, contact point 175, and thence to ground.

The release of the central otiice switching apparatus is brought about when the calling subscriber restores the receiver 2 to the switch-hook 3, thereby pressing the release springs 32, 33A and 34 into contact and grounding both line conductors 92 and 93 simultaneously. Grounding both line conductors at this' time shunts or short-circuits the rotary line relay 76 and winding 90 of the differential relay 88. This shunt extends from ground Gs, contact point 140, side switch wiper 85, springs 172 and 173, con- ,ductor 156, ringer relay springs 154 and 121,

winding .90 of the differential relay 88, rotary line relay 76 to the rotary line conductor 98, through the release springs 33 and 32 to the substation ground G. The differential relay 88 then cnergizes and the sprin s 143 and 144 are disengaged, whereby t e ringer relay returns to normal position, thus allowing the spring 121 to rengage the spring 122. T he short-circuit of the rotary line relay 76, in series with the winding 90, is thereby removed and an energizing circuit is established instead, over previously traced circuits, through the release sprin s 3S and 32 to the substation ground G'. Te rotary line relay 76 energizes and operates in conjunction with the vertical line relay 75 to place the trunk-release springs 179 and 180 in contact, thereby closing an energizing circuit through the connector release magnet 79 in series with the back-release relay 52 of the first-selector C. This release circuit extends from ground G, contact point 111. side switch wiper 44, through the release relay 52. shaft wiper 41, conductor 181, trunk-release springs 179 and 180, release magnet 79. conductor 120, through tluringer relay springs 121 and i122 to the battery lcad 97, thence through battery B and to ground G. The release magnet, upon energizing. operates to restore the side switch F and the switch shaft to normal position, in the manner explained in the said relay 91 is wound to a resistance of tivo hundred ohms; the ringer relay 81 to thrce` hundred ohms; and the windings 89 and 90 of the diierential relay S8 to seventy-ve ohms each.

From the foregoing it will be seen that I provide means for giving common battery telephone service to the subscribers of an automatic exchange wherein one or more of such subscribers may have a plurality of telephones any one of which will answer the purpose of a calling subscriber. The automatle switch D is adapted to operate automatically until ittinds an idle line running to the station of a called subscriber, or to the oflice at which several telephones are located, and is equip ed with means responsive to the called su scriber for then admitting talking current to the callin and called` telephone lines. It will be un erstood, of course, that the automatic switches D, which may be called rotary connectors, are preferably less in number than the total number of subscribers, so that the trunking between telephone lines is conducted on a percentage basis. With such arrangement the subscribers individual switches C, which are herein illustrated as first-selectors, will be the. same in number as the total number of telephone lines. l't will also be understood that for a larger exchange additional selectors can be employed and arranged intermediate of the selectors C and the rotary connectors D, in a well-known manner.

It will be seen that the selectors and oonnectors herein disclosed are of that type in which vertical or straight line motion is employed. for selecting groups, while rotary motion is employed for connecting with a line in the selected group, the system being of that character in which the subscribers are divided into groups. The vertical or straight line mot-ion of the selectors is for the purpose of selecting the sections or divisions into which the groups of subscribers are divided, and each level in a selector represents a different group of trunks. In the connectors each level or horizontal row of bank contacts represents a group of sub scribers lines, so that in calling a subscriber first selects the section or division in which thc called subscribel"s group is found. and then by means of the connector selects the particular group of subscribers lines, all of which subscribers `lilies may. with the arran ement shown, be allotted to one subscri er. In such case, as explained, the

action of the connector, after the desired level or Group of lines is selected by the calling su scriber, is then purely automatic,

it stops on the first idle subscribers line. lVhat I claim as my invention is l. The combination of a plurality oi telephone lines, subscribers telephones on said lines, means by which a calling subscriber automatically selects the first idle one of said lines, and means under the control of the called subscriber for supplying talking current to the calling and called telephone lines.

f2. In a telephone system, the combination of a plurality of telephone lines, subscribers telephones on said lines, means by which a calling subscriber automatically selects the first idle one of said telephone lines, and means under the control of the called subscriber for supplying talking current to the calling telephone line.

3. In a telephone system, the combination of a calling subscribers line and of a plu rality of lines, a plurality of rogressively movable switches by means o any one of which a calling subscriber automatically selects the lirst idle one of said lines, and means individual to each switch under the control of the called subscriber for supplying talking current to the calling telephone line.

4. In a telephone system, the combination of a plurality of telephone lines running to the same substation, telephones on said lines. an automatic switch provided with means for extending connection to any one of said lines, automatic means for Causing the operA ation of said switch to select the first idle one "of said lines, a common battery, and a relay .allotted to said switch and controlling the flow ot talking currentfrom said battery to the calling telephone line, said relay controlled by the called telephone line for supply/ing current for talking purposes to the calling telephone line.

5. In a telephone system, the combination of a plurality of telephone lines running to the same substation, telephone sets on said lines, an automatic switch provided with means for extending connection from a calling telephone line to any one of said telephone lines, automatic means for operating said switch to select the first idle one of said lines, and a common battery. said switch provided with a relay controlled by one of said telephone lines for controlliiiggr the flow of talking current from saidbattery to the calling telephone line. l

6. In a telephone system, the combination of telephone lines telephones on said lines, automatic means or trunking a calling line into connection with the line of a called aubscriber, automatic means for causing the selection of the first idle one of a group of said telephone lines, and automatic means controlled by the subscriber of the idle telephone line for sup lyin talking current to the calling and cal ed telgephone lines.

7. In a telephone system, a calling line, a substation on said line, a plurality of other lines, an automatic switch for selecting idle lines adapted to malte connection with some, one of said linesunless the same are all busy, a central source of current, and means including a relay in said switch controlled by an* one olE said other lines for supplying tal ing current from said source through the said switch to the calling snbscribei"s substation.

8. In a telephone system, a source of talking current a combined automatic selector and connector switch, and a back-bridge relay in said switch for controlling the su ply of talking current to the calling' subscribers station when the called subscriber answers. P

9. In a telephone system, the combination of a calling subscribers line and of a plurality of lines, automatic means for selecting and extending connection to idle lines, means for signaling a called subscriber, a source of current, means associated with the lineselecting means for connecting the source of current to the automatically selected line, means controlled by said called subscriber for supplying current for talking purposes from said source to said calling subscribers line, and automatic means for releasing.

l0. In a telephone system, a plurality of lines, a switch adapted to operate at dillen ent levels, means in said switch for selecting a level in accordance with a certain digit of the called number, means in said switch for then causing the operation thereof in the selected level in accordance with another digit of said number, means in said switch for then automatically continuing the operation untii an idle line is found, and auto matic means for supplying the selected line with current.

il. In a telephone system, and in combination with a common battery. an automatic common battery switch having a private relay and a private magnet and a rotary line relay for operating the private relay, for in turn operating the private magnet, a side switch, and a rotary magnet, said private relay adapted to prevent the energizing of said rotary magnet while said private magnet is energize and while the side switch is in second position.

l2. In a telephone system, a common battery switch, a plnralitybt line terminals divided into contact levels, said switch pro vided with a shaft, means in said switch for operating said shaft to elect a contact level, a rotary manet, means for first energizing said magnet y a plurality of impulses from the calling substation, and means for then telephones on sai to automatically select automatically energizing said magnet after said shaft has reached a certain point.

18. In a telephone system, an automatic switch provided with line conductors,a battery a ringer generator disconnected from the battery, a ringer relay for use in signalf ing the called subscriber, means by which said ringer relay is adapted toswitch one of said line conductors from one pole of said battery to the other, a plurality of lines, and meansin said switch for automatically selecting an idle line.

14. In a telephone system, a plurality of subscribers lines any one of which will serve the purpose of a calling subscriber, means including an automatic switch for automatically selecting an idle one of said lines for the calling subscriber, and means associated with said automatic switch 'and controlled by the selected line for supplying talking current to the calling subscribers substation.

15. The combination of a plurality of telephone lines, subscribers telephones on said lines, means by which a calling su`bscriber automatically selects thefirstidle one of said lines, including a rotary connector having straight motion to select groups and rotary motion to automatically select the first idle line in the selected group, and means under the control of the called subscriber for supplying talking current to the callin and called telephone lines.

16. n a telephone system, the combination of a plurality of telephone lines, subscribers lines, means by which a calling subscriber automatically selects the first idle one of said ,telephone lines, including a rotary connector having straight motion to select groups and rotary motion the first idle line in and means under the control of the'called subscriber for supplying talking current to the calling telephone line. 17. In a telephone system, the combination of a plurality of telephone lines.l subscribers telephones on said linesJ means b, which a calling subscriber automatically selects the first idle one of's'aid telephone lines, including a connector having one moiement to select groups and a second motion to automatically select the first idle line in the selected group, and means individual to said connector under the control of the called subscriber for supplying talking current 1o the calling subscribers telephone line.

18. In a telephone system, the combination of a plurality of telephone lines running to the same substation, telephones on said llnes, an automatic switch provided with means for extending connection to any one of said the selected group,

lines, automatic means for causing the operation of said switch to select the lirstidle groups and rotary one of saidlines, said switch having vertical motion'to select groups and rotary motion to automatically select the first idle line in the selected group, a common battery, and relays allotted to said switch and controlling the flowcf talking current from said battery to the called telephone line.

19. In a telephone system, the combination of a plurality of telephone lines running to the same substation, telephones on said lines. an automatic switch provided with means for extending connection from a calling telephone line to any one of said telephone lines, automatic means for operating said switch to select the first idle one of said lines, said switch having vertical motion to select groups and rotary motion to automatically select the first idle line in the selected group` a common battery, and rclays allotted to said switch and controlling the flow of talking current from said battery to the calling telephone line.

. 20. In a telephone system, the combination of telephone lines, telephones on said lines, automatic means for trunking a calling line into connection with the line of a called subscriber, automatic means for causing the selection of the first idle one of a group of said telephone lines, including a rotary connector having straight motion to select groups and rotary motion to automatically select theV first idle line in the selected group, and automatic means controlled by the subscriber of the idle telephone line for supplying talking current to the calling and called telephone ines.

21. In a telephone system, \a source of talking current, an automatic switch, said switch having vertical motion to select motion to automatically' Select the first idle line in the selected group, and a back-bridge relay in said switch for controlling the supply of talking current to the calling subscribers station when the called subscriber answers.

22. In a telephone system, a source of talking current, a combined automatic selector and connector switcb.said switch having vertical motion-to select groups and rotary motion to automatically select the first idle line in the selected group, andv a backbridge Vrelay in said switch for controlling the supply of talking current to the calling subscribers station `when the called subscriber answers.

` 23. In a telephone system, the combination of calling subscriber-s line, and of a plurality of called lines, automatic means for selecting and extending connection to said called lines, including a connector having w rent, means for connecting the source of current to the 'automatically selected called line, through said line-selecting ineens,A means controlled by said called line tor supplying current for talking purposes to said calling subscribes line, and automatic means for releasing. s

24. ln a telephone system, andln combination with a common battery, an automatic common batter switch having a priyate relay and a private magnet, and provided with a rotary line relay for operating said private relay, for operatin 1n turn the pnvate magnet, a side swltc and an o r ating magnet, said private relay adapte l to prevent the energizing of said operating magnet while said private magnet is energized and while the side switch is 1n second position, said switch having one n ioa tion ect grou s and a second to au.1V @i 'l se ect the first idle line in the enlisted g p telephone system, an automatic ewitce` provided with line conductors, said switch having,r vertical motion to select groups and rot-arg,T motion to automatically select the First idle line '1n the selecte group, a battery, rin relay for use in s' nalin the called subscriber, means by which sai ringer relay adapted to switch-one of said line conductors from onepole of said battery the other, a plurality of lines, and means in said switch for automatically selecting an idle line.

2t. ln a telephone exchange system, the combination with a line switching device carrying one group of line terminals and a second group of line terminals any one of which will serve the purpose of the calling line, of a moving Contact member for said switching device, automatic means for moving said member to any of said line terminals of said first group or the first terminal of said second group, and means actuated in case the first terminal of said second group is busy for stepping said vmember-.to a. terminal of an idle line in said. second group.

Q7. In a telephone exchange System, the munbination with a telephone .line extending 'from a sulijstation to a central oiiice.y of :t connecting circuit at the central oiicc, a connection switch -for uniting said connecting circuit with the telephone line.y a line switching device carrying terminals for one set of lines in the exchange, a second set of lines any one of which will serve the purpose of the calling subscriber leading to terminals of said device, a contact arm for said mechanism adapted to move over said terminals to unite said connecting circuit with said terminals, autornaticallji.V operated mechanism advancing' said arr` over said terminals over sail second set of terminals until an idle line is reached, a busy signal, and means actuated in case all of said secondL set of lines are busy for ap plying said busy signal to said connecting circuit.

28. The combination with a telephone switching mechanism provided with transmission line terminals and two groups of testing line terminals, of substation lines having third conductors connected to one group of test terminals, and groups of lines with their third conductors connected to the other group or" test terminals.

29. A telephone system comprising a plurality of lines, a telephone for each line, and means for connecting each telephone to its line, an automatic switch provided with means for automatically selecting an idle one of said lines to set up a talkin circuit between two of said lines, the telep one of one line acting as a calling telephone and the telephone on the other line acting as a called telephone, and means in said switch responsive to the called telephone for con trolling the suppl",T of talking current to the calling telephone line, the circuit between the connected telephones being divided into only two iniiurtively connected sections.

56. A telephone system comprising a calling substation, a called substation, a plurality of lines, an, automatic switch provided with means for automatically selectin an idle one of said lines to set up a tal ing `circuit between said substations, relays indi vidual to said switch, means for supplying talking current through the winding of Said relays to the calling substation, and another relay associated with said switch and responsive to the calledsubscriber for controlling the supply of talking current to the substation of the calling subscriber, the said talking circuit being divided. into onlyT two inductively connected sections.

31. 'The combination of lines, substations ou said lines, a switch having provisions for automatic rotation to automatically select idle lines,v a calling subscribers substation.` a called suhseribers substation. means for operating the said switch to set up a talk ing circuit between a calling and a called substation. and means individual to said switch and responsive to the called sub scriber for controlling thc supply of talk-- ing current to the substation of the calling subscriber, the said talking circuit being dil vided into only two inductively connected sert-ions.

32. ln a telephone systenn'a pluralitv of subscribers lines divided into roupsi'and subgroups. and an automatic swltch having one controlled movement to select'a predetermined group. a second controlled more ment to select a predetermined sub-group and a third automatic selecting movement to naanoo? connect with an idle line in group.

a selected Sub- 33. In a telephone s stem, a plurality of subscribers lines divi ed into groups and sub-groups, an automatic switch having one movement to select groups, a second movement to select sub-groups and a third movement to connect with a line in a selected subgroup, and common battery means for supplying talking current to said lines.

34. In a telephone system, a plurality of subscribers lines divided into groups and subgroups, an automatic switch havin one controlled movement to select a pre eterniined group, a second controlled movement to select a predetermined sub-group and a third automatic selecting movement to connect with an idle line in a selectedsubgroup, and common battery means for supplying talking current to said lines.

` In a telephone system, the combination of a line, a switch associated with said line. a group of telephone lines and a terminal for each line in said switch, a, test circuit for each line, means operated over the lines of said group for establishing a guarding potential to said test circuits for making lines in said group busy, automatic means for operating said switch to find the group of lines, and automatic means for causin the operation of said switch to select the first idle one of said lines, a common battery, and coils associated with said switch -to Acontrol the flow of talking current from said battery to the called telephone line.

36. In a telephone system` the combination of a line, a switchassociated with said line, a group of telephone lines, a substation for each line and a terminal for each line in said switch. means controlled from the substations for making lines in said group busy, automatic means for operating said switch to find the group of lines, and automatic means for causing the operation of said switch to select the lirst idle one of said lines, a common battery. and 'coils associated with said switch to control the flow of talking current from said battery to the called substation. v

il?. ln a telephonesystem, a plurality of subscribers lines. any one of which will serve the purpose of thecalling Subscriber, means controlled by one of said subscribers and including an automatic switch for autoinaticallyv selecting an idle line for the callingr subscriber. and means associated with said automatic switch for supplying talking curi-cnt to a subscribers station.

3R. ln a telephone system, a plurality of subscribers lines. any one of which will serre the purpose of the calling subscriber, nicnns controlled by a plura ity of subscribers and including an automatic switch for automatically selecting an idle line for 'group of .lines terminating the calling subscriber, and means associated with said automatic switch for supplying talking current to a subscribers station.

39. In a telephone system, a line, a switch for said line, a group of lines terminating in said switch, a second group of lines terminating in said switch, means for operating said switch over the said iirst line to estab- Iish connection with any one of the lines in the first group exclusively as a result of a numerical operation of the switch, means for operatin said switch over said first line for establishing connection with some one of the lines in the second group involving a non-numerical operation of the switch, the operation of sald means controlled from lines in said second group.

40. In a telephone system, the combination of a plurality of teiephone lines, subscribers telephones on said lines, means by which a calling subscriber automatically selects the first idle one of said telephone lines including a switch having means responsive to the last digit in the number of the called line, said switch having one movement to select groups and another movement to automatically select the first idle group, and means under the control of the called subscriber for supplying talking current to the called telephone line.

41. In a telephone system, a calling line, a switch associated with said line, one group of lines terminating in said switch, a second group of lines terminating in said switch, means responsive to numerical operations for establishing connection with any one of the' lines in the first group, and automatic means responsive to non-numerical operations to establish connection with lines in the second group, said automatic means controlled from lines in the second oup.

42. In a telephone system, a cal ing line, a switch associated with said line, one group of lines terminating in said switch, a second in said switch, operable moving switching equipment individual to each of said lines, means res onsive to numerical operations for establis ing connection with any one of the lines in the first group, and automatic means responsive to non-numerical operations to establish connection with lines in the second cup, said automatic means controlled by said operable moving switching equipment.

-lifln a, telephone system. a group of lines, a second group of lines, a switch having terminals for said lines, switching means individual to said lines. numerical automatic operating means for finding either group and for finding a line in the Erst group after the first group is found, and non-numerical means for finding a line in the Second group after the second group is found, said non-numerical means controlled from line in the selectedA the said last line by said switchin means to select another line, a common attery, and means associated with said switch for controlling the flow of current for talking from said batter to said other line.

44. In a telep one system, a group of lines, a second group of lines, a switch having terminals for said lines, numerical automatic operati means for finding either group and for dingaline in the first group after the first grou-p is found and non-numerical means or nding a linewin the second group after the second grou is found, movable switching means indivi ual to the lines of the said second group for making said lines busy, said automatic non-numerical means controlled from said movable l switching means for operating said switch to select the first idle one of said lines of the second group, a'common battery, and means associated with said switch for controllingthe liow of current for talking from said battery to said line when found.

45.'In a telephone system, a ou of lines, a second group of lines, a switch aving terminals for said lines, numerical automatic operating means for finding either group and for finding a line in the first group after the first oup is found and non-numerical meansor finding a line the second group after the second group is found, means operated over the lines of said second group for maln'ng lines in said grou busy, said non-numerical means controllo by said line operated means for operating the said switch to select the first idle one of said lines in the said second group, a common battery, and means associated with said switch for controlling the flow of current for talking from said battery to the called telephone line.

46'. In a telephone system, a oup of lines, a second group of lines, a switch having terminals for said lines, numerical' automatic operating means for fndin either group and for finding a line in t e rst group after the first groufp is found, and non-numerical means for nding a line in the second group after the second group is found, a Telephone for each of said lines, and means controlled from the telephone for making lines in said second group busy, said automatic non-numerical means controlled' from said busy making means for operating said switch to select the first idle one of said lines, a common battery, and

means associated with said switch for controlling the flow of current for talkin from said battery to the called telephone ine.

47. ln a telephone system, a plurality of lines, automatic means for selectlng the flrst idle line including a switch having means responsive to the last digit in the number of the called line, having one motion to select groups and another motion to automatically select the first idle line in the selected group, a common battery, and automatic means for closing connection to supply talking current .to a subscribers station.

the called line, said switch having onemof tion to select groups and another motion to automatically select the first idle line in the selected grou and means for signaling a called suhscri er, a source of current, means for connectin the source of current to the vautomatic se ccted line, and auto matic means for releasing.

49. In a telephone system, a plurality of lines any one of which will serve the purpose of a calling subscriber, means including an automatic switch having equipment responsive to the last digit in the number of t e called line for automatically selecting an idle line for the calling subscriber, said switch having one motion to select groups and another motion to automatically select the first idle line in the selected group and means for automaticaliy supplying tallu'ng current to a subscribers station.

50. In a telephone system, a common battery automatic switch having means re sponsive to the last digit in the number of the called line and having revisions for selecting the first idle one o a nuinber of lines common to a single subscriber, and means for feeding talkin current to any called line thus automatica ly selected.

51. In a telephone system, an automatic switch, automatic means for trunking a calling subscriber into connection with said automatic switch, said switch having means responsive to the last digit in the number of the called line and havin provisions for automatically selecting the rst idle one of a' number of lines common to a single suhscriber in combination with means for supeI plying talking current to any called line thus automatically selected.

52. A telephone s stem comprisin a calling substation, a cal ed substation, a p urality of lines, an automatic switch having means responsive to the last digit in the number.

of the alled station and provided with means f r automatically nselecting an idle one of said lines, relays, means for supply- 'ing talking current through the windings of said relays to the calling substation and another re ay responsive to the called subscriber for controlling the supply of talking current to the substation of the calling subscriber.

53. The combination of lines, a switch having provisions for operating in accordance with the last digit in the number of a called subscribers station and having provisions for automatically rotating to select idle lines, a callinv subscribers substation, a` called subscribers substation, and" means responsive to the called subscriber for controlling the supply of talking current to the substation of the calling subscriber.

54. In a telephone system, the combination of a plurality of lines, automatic means for selecting and extending connection to idle lines, said means responsive to the last digit in the number of a called line, means for signaling a called line, a source of current, means associated with the line selecting means for connecting the source of current to the automatically selected line, and automatic means for releasing.

55. In a telephone system, a line, a progressively mova le sw itch for said line, terminals for said switch, a station, lines extending from said station and terminating in said terminals, any one of which lines will serve the purpose of the first line for extending a connection to said station, a telephone individual to each line, a signal for each line, means in said switch for autonnitically selectingr an idle one of said lines and for then operating the si al thereof, a switch for the called line or connecting the telephone thereof with the line in response to said signal, and a central battery for supplying current. for talking purposes to the first line and to the called line.

56. In a telephone system, a line, a pro gressively movable switch for said line, terminals for said` switch, a station, lines extending from said station and terminating in said terminals, any one of which will serve the purpose of the first line for extending a connection to said station, a telephone individual to each line, a signal for each line, means in said switch for automatically selecting an idle one of said lines and for then operating the signal thereof, a switch for the ca led line` :for connecting the telephone thereof with the line in response tosaid signal, a. central battery for supplying currentfor talking purposes to the first line aand, to the called line, and means for conti-olling the supply of said current to said first line, said means controlled over the called line.

57. In a telephone system,"a line, a pro gressively movable switch for said line, terminals for said switch, a station, lines extending from said station and terminating in said terminals, any one of which will serve the purpose of the first line for extending a connection to said Station, a telephone individual to each line, a signal for each line, means in said switch for automati cally selecting an idle one of said lines and for then operating the signal thereof, a

V:la

switch for the called line for connecting the telephone thereof with the line in response to said signal, a central battery for supplying current for talking purposes to the first line and to the called line, and a relay for controlling the supply of said current to said first line, said relay controlled over the called line.

58. In a telephone systein,a line, a progressively movable switch for said line, terminals for said switch. a station, lines extending froni said station and terminating in said terminals, any one of which will serve the purpose of the firstyline for eX- tending a connection to said station, a telephone individual to each line, a signal for each line, means in said switch for automatically selecting an idle one of said lines and for then operating the signal thereof, a. switch for the called line for connecting the telephone thereof with the line in response to said signal, a central battery,and means individual to each progressively movable switch for applying said battery to the first line for talking purposes.

In a telephone system, a line, a progressively movable switch for said line, terminals for said switch, a station, lines extending from said station and terminating in said terminals, any one of which will serve the purpose of the first line for extending a connection to said station, a telephone in ividual to each line, a signal for each line, means in saidvswitch for automatically selecting an idle one of said lines and for thenoperating the signal thereof, a. switch for the called line for connecting the telcphone thereof with the line in response to vsaid signal. a central battery, and means individual to each progressively movable switch for applying said battery to thc first line for talking purposes, said means controlled over the called line.

60. In a telephone system. aline, a line switch for said line, a plurality ot progressiveiy movable switches, means for operating said line switch to connect said line with any one of said`switches, line terminals for one of said switches and multiples thereof in the other switches, a station, other lines extending from said station and terminating in said terminals, any one of which switches and any one of which other lines will serve the purpose of the said first line for extending a connection to said station, a telephone individual to each line, a signal for cach line, means in all of said progressively movable switches whereby any one of said switches may be operated to automatically .select an idle one of said lines after the first line has been connected to one of said switches and for then operating the signal of the selected line, an auxiliary switch for the called line for connecting the telephone thereof with the `ine in response to said signal, and a central battery for supplying current for talking purposes to the first line and to the called line.

6l. In a telephone system, a line, a iine switch for said line, a plurality of progressively movable switches, means for operating said line switch to connect said line with any one of said switches, line terminals for one of said switches and multiples thereof in the other switches, a station, other lines extending from said station and terminating in said terminals, any one of which switches and any one of which other lines' will serve the purpose of the said first line for extending a connection to said station, a telephone individual to each line, a signal for cach line, means in all of said progressively movable switches whereby any one of said switches may he o ierated to automatically select an idle one o said lines after the first line has been connected to one of said switches and for then operating the signal of the selected line, an auxiliary switch for the called line for connecting the telephone thereof with the line in response to said signal, a central battery for suppiying current for talking purposes to the first line and to the called line, and means for controlling the supply of said current to said first line, said means controlled over the called line.

62. In a telephone system, a line, a line switch for said line, a plurality of progressively movable switches, means for operating said line switch to connect said line with any one of said switches, line terminals for ono of said switches and multiples thereof in the other switches, a station, other lines extending from said station ,and terminating 1n said terminals, any one of which switches and any one of' which other lines will serre the pur pose of the said first line for extending a connection to said station, a telephone individual to each line, a signal for each line, means in all of said progressively movable switches whereby any one of said switches may he operated to automatically select an idle one of said lines after the first llne has been connected to one of said switches and for then operating the signal `of the selected line, an auxiliary switch for the called line for connecting the telephone thereof with the line in response to said signal, a central battery for supplying current for talking purposes to the rst lincand to the called line, a relay for controlling the supply of said current to said first line, said relay controlled over the called line.

63. In a telephone system,'a line, a numerical line switch for said line, a plurality of progressively movable switches associated with said first switch, means for operatm said first switch in response to a numerica impulse to connect said line with any one newness of said progressively' metal 'f terminals for one of said aille switches and inattivi other progressi vcly moral? tion, other lines extending iioni sa and terminating in said terminale, any one oi which switches and any` Yone of which other lines wiil serve the purpose of the said first line for extending connection to said station, a teicphone individual to each line, a. signal for each line, means in all of said progressively movaloie switches whereby an one of said switches may be operated to auf o matically select an idle one of said lines after the first line has been connected to one of said switches and for then operating the nal of the selected line., an auxiliary switch for the called line for connecting the telcphone thereof with the line in response 11o said signal, and a central battery fer suppiying current for talking purposes to the iirst iine and to the called line.

64. In a telephone syst-em, a lino, an automatic switch for said line, terminals for said i' ed with sgi-maps, said switch selig-rl groups of terminals lor finding a` terminal t i, lines extend ing from s n. terminating in said reunir y which will serve the purpose ci" the first line for extending a connection to iid station, a telcpl'ionc individual to nach iinc, a signal for each line, means in said switch for automatically se lccting an idle one of said lines and for then operating the signal thereof, a switch for the called line for connecting the telephone thereof with the line in response to said signal, and a central battery for supplying current for talking pin-poses to the first line and to the called line.

65. ln a telephone system, a line, a line switch for said line, a plurality of automatic switches, means for operating the said line switch to connect said line with any one of' said switches, line terminals for one of said switches divided into groups and multiples thereof in the other of said switches, said switches having motion to select groups ot' terminals and a second motion to find a terminal in the selected group, a station.y other lines extending ,from said station and terminating in said terminals, any one ci whlch switches and any one of which other lie s will serve the purpose of the said first line for extending a connection to said staand a o1 in a selected f "tion, a .telephone individual to each line, a

'been connected to one of said switches and for then operatingthe signal of the selected line, an auxiliary switch for the called line `tomatically select an i 4signal of the selected line,

:for connecting the telephone thereof with the line in response to said signal, and a central battery for supplying current for talking purposesto the rst line and to the called line.

66. In a telephone system, a line, a numerical line switch for said line, a plurality of automatic switches associated with Said line switch, means for operating said' line switch in response to a numerical impulse to connect said line with any one of said autonyatic switches, line terminals for one of said automatic switches divided into groups and multiples thereof in the other automatic switches, said switches having motion to select groups of terminals and a second motion to find a terminal in the selected group, a station, other lines extending from said station and terminatin in said termlnais, anyone of which switc es and any one of wliichiother lines will serve the purpose of the said first line for extending a connection to said station, a telephone individual to each line, a signal for each line, means in all of said switches whereby any one of said switches ma be operated to audle one of said lines after the first linehas been connected to one of said switches and for then operatin the an auxi iary switch for the called line for connecting the telephone thereof with the line in response to s aid signal, and a central battery for su tacts individualY plying current for talking purposes to t e first line and to the called line.

67. In a telephone system, a telephone station, a central office, a line connecting the station and the office, a progressively movable switch at the central oiiice for extending a connection from said line, a motor magnet for imparting motion to said switch, a circuit including said magnet, a relay, conto said relay, said circuit including said contacts, a circuit for the relay including the line, a circuit controller for said line for sending an impulse over the line` for energizing said relay whereby said relay in turn may energize the motor magnet to advance the switch while the relay is energized. a plurality of other lines, a telephone individual to each other line, means for operatively associating each telephone with its line. a terminal for each line at said progressively movable switch, means in said progressively movable switch whereby the motion of said switch may be initiated by an impulse over said first line,nie.ans in said progressively movable switch and associated with said terminals fory causing the motion to persist until thc switch passes over several of said terminals while the circuit controller of the first line is not changing the condition of the line circuit, means in said switch for connecting the rst line and any one of said other lines when the motion ceases to establish a talking circuit between the two, a central source of batter for supplying current to the line for tal ing purposes, a signal on the line to which connection is extendcd,.a source of signaling current, and means for transmitting said current to said s gnal through said. progressively movable Swich.

68. In a telephone system, a station, a central oilice, a line connecting the oiiice and the station, a progressively movable switch at the oiiice for extending a-connection from said line, a motor magnet for the switch, a

i circuit for the magnet, a relay for controlling the motor magnet circuit, a circuit for the relay including the line, a circuit controller for said line for sending an impulse over the line for energizing said relay to close Jthe motor magnet circuit, a plurality of other lines, a telephone individual to eac other line, means for operatively associating each telephone'with its line, a terminal :for each line at, said progressively movable switch, means in said progressively movable switch whereby the motion of said switch may be initiated by an impulse over said first line, means in said progressively movable switch and associated with said terminal for causing the motion to persist until the switch asses over several of said terminals whi e the circuit controller of the first line is not changing the condition of the line circuit,` means 1n said switch -for connecting the first line and any one of said other` lines when the motion ceases to establish a talking circuit between the two, a central source of battery for supplying current to the line for talking purposes, a'signal on the line 'to which connection is extended, a source of signaling current, and means for transmitting said 'current to said signal through the said progressively movable switch.

69. In a telephone system, the combination of a plurality of lines, a telephone receiver for each ine, a switch, automatic means for causing the operation of said i, switch to select any idle one of said lines, means individual to each line for operatively associatin each receiver with its line, a. common attery, a rela allotted to said switch'and controlling t e iiow of talkingA current from said battery to the selected line, and means for effecting said current to etl'ect said receiver for talking.

70. In a telephone system, a line, a telephone for talking over said line, a switch, a group of lines, a test circuit for each line of the group, a relay for said switch, means for moving the switch, said means controlled by said relay and controlled `by said test circuits to continue the movement of the switch until an idle line in the group is found whereby a connection may be extended from the first line to the idle line, and means for supplying current for talking purposes to sal tele hone through the winding of said relay w ile the connection is maintained, said means for moving the switch comprising a motor magnet, a circuit for said motor magnet and contacts in said circuit individual to said relay whereby the relay armature controls the motor magnet circuit. l

71. In a telephone system, a line, a telephone for talking over said line, a switch, lines divided into groups, a relay for said switch, means for moving said switch, said means controlled by said relay' for electing a group of said lines and controlled by said lines whereby a connection may be extended from the first line to any line in the elected group, and means for supplying current for talking purposes to said telephone through the Winding of said relay while the connection is maintained, said means for moving the switch comprising a motor magnet, a circuit i'or said motor magnet and contacts in said circuit individual to said relay whereby the relay armature controls the motor magnet circuit.

72. In a telephone system, a line. a telephone for talking over said line, a switch, lines divided into groups, a relay for said Switch, means `for moving said switch; said means controlled by said relay for electing a group of said lines and for initiating a line selecting operation in the elected group, said means also controlled by said lines whereby a connection may be extended from' Vthe first line to any line in the elected group, and means for supplying current :for talking purposes to said telephone through the winding Aot' saidrelay while the connection is maintained, said means for moving the switch comprising a motor magnet, a circuit for said motor magnet and contacts in said circuit individual to said relay whereby the Ueli ci this patent my be obtained for relay armature controls the motor magnet circuit.

73. A telephone system comprising a plurality of telephone lines running to the same substation, telephones on s* id lines, an automatic switch provided wi `h means for ex` tending connection to any one of said lines, automatic means for causing the operation of said switch to select the first idle one of said lines, a common battery, and a relay allotted to said switch and controlling the flow of talking current from said battery to the calling telephone line.

74. In a telephone system, a plurality of lines, xed terminals of said lines arranged in groups and, sub-groups, an automatic switch provided with a movable terminal cooperating with said fixed terminals, directly controlled means for causing successive operations of said movable terminal to select a group and sub-group of fixed terminals, and automatic means for then operating the said movable terminal to select an idle ixed terminal in the selected sub-group.

75. In a telephone system, a pluralit of groups of lines, fixed terminals of said ines arranged in a single horizontal group, an automatic switch having a movable terminal coperating with said fixed terminals, means for operating said switch to cause the movable terminal thereof to pass by all the fixed terminals corresponding to one of said groups oil? lines, and means for then automatically operating said switch to cause the said movable terminal to select a fixed terminal corresponding to an idle line in another one of said groups of lines.

Signed by me at Chica o, Cook county, Illinois, this 21st day of l\ arch, 1907.

TALBOT G. MARTIN.

Witnesses EDWARD D. FALEs, ARTHUR B. Srnimx.

ive nenti each, by addressing the Commissioner o! Patenti,

Washington, n0." 

